Grinding attachment for bicycles.



N9. 875,806. PATENTED JAN. 7, 1908.

J. P. GRANT. GRINDING ATTACHMENT FOR BICYGLES.

APPLICATION FILED MAY 21, 1907 arana orrrcn.

JAMES P. GRANT, OF BERKELEY, CALIFORNIA.

GRINDING ATTACHMENT FOR BIGYCLES.

Specification of Letters Patent.

Patented Jan. 7, 1908.

Application filed May 21, 1907- Serial No. 374.873.

To all whom it may concern:

Be it known that I, J AMES P. GRANT, a citizen of the United States,residing at Berkeley, in the county of Alameda and State of California,have invented certain new and useful Improvements in GrindingAttachments for Bicycles, of which the following is a specification,reference being had therein to the accompanying drawing.

This invention relates to improvements in grinding devices, and has forits object the provision of means for facihtatlng the rotation of agrinding element detachably supported upon a bicycle frame.

Another object of the invention is the construction of a grindingattachment for bicycles, which comprises a minimum number of parts, issimple in operation, and comparatively inexpensive to construct.

With these and other objects in view, the invention consists of certainnovel constructions, combinations, and arrangements of parts, as will behereinafter fully described and claimed.

In the drawings: Figure 1 is a view in side elevation, of an attachmentconstructed in accordance with the present invention, and showing thesame secured to a bicycle frame. Fig. 2 is a plan view of thegrinding-wheel or element supporting device, while Fig. 3 is a lan viewof the driving-member supporting device through the medium of which thegrinding-wheel is driven orrotated. Fig. 4 is a view, in side elevation,of the arm carrying the belt-tightening ulley. Fig. 5 is a view in sideelevation of t 1e auxiliary clamp, upon which is sup orted the shaftcarrying the friction whee and the rear pulley.

Referring. to the drawings by numerals, 1 designates the front, guidingpost of an ordinary bicycle frame, and 2 the rear forks or seat posts.The horizontal bar 3 connects the front and rear posts 1 and 2.

My improved grinding attachment comprises a air of devices, one of whichcarries the grin ing wheel and the other a friction wheel anddrivingpulley, through the medium of which the grinding-wheel isrotated. In the following description, I shall refer to the devicecarrying the grinding-wheel or member as the grinding-wheel supportingdevice, and to the rear device carrying the driving-member as thedriving-member supporting device, to facilitate the description of myattachment.

The grinding-wheel supporting device comprises a clamp 4:, which is comosed of clampmembers 5 and 6. Each of t iese members 5 and 6 is providedat its outer end with a curved portion 7, constituting a socket upon theclamp 4, within which is positioned the front post 1. The horizontal bar3 is positioned between the clamp-members 5 and 6, as clearly seen uponreferring to Fig. 2. A block 8, constituting an enlarged portion uponthe clamp-member 5, is secured to said clamp-member 5, and ascrew-threaded bolt or screw 9 extends through the clamp-memher 6 nearits inner end, and is threaded through the clampanember 5 into block 8.Between the outer ends of the clamp-memb ers 5 and 6 and bolt 9, isanother screw-threaded bolt or screw 10, which bolt 10 extends throughmember 1 and is threaded, preferably, through the clamp-member 5.Through the medium of bolts 9 and 10, the clampmembers are secured uponthe post and bar 1 and 3, respectively.

The block 8 is provided with, preferably, a longitudinally-extendingaperture, within which is adjustably and detachably secured a shaft 11.The shaft 11 is secured in an adjusted position upon block 8 through themedium of thumb-screw 12. The thumb screw 12 is threaded into block 8and engages, at its inner end, the shaft or supporting-bar 11. A spindleor axle 13 is secured near the upper end of shaft or bar 11, andjournaled upon this axle 13 is a grinding-wheel 1 1 and a belt-pulley15. The wheel 14 and pulley 15 are keyed against independent, rotarymovement upon shaft13.

The thumb-screw 13 is screw-threaded upon its shank throughout itslength, and upon the shank is threaded a thumb-nut 16, between which nut16 and block 8 is positioned a detachable arm 17, which arm is curvedthroughout its length, see Fig. 4, and is bent inwardly, as at 19, andjournaled upon the extreme upper end, is a belt-tightening pulley 20.The lower end of the arm is, preferably, slitted or bifurcated, as at21, so that the same may be easily removed off of block 8 by looseningthe clamp thumb-nut 16, or said arm may be adjusted to keep the endlessbelt 22 tight.

The driving-member supporting device comprises a clamp 23. This clampcomprises a substantially Ushaped body 24, l which is formed,preferably, from a single piece of resilient metal, the ends of whichpiece are bent back parallel with the remaining portion of the body forconstituting reinforcing means for said body, the extreme ends of thebody being slightly outwardly curved, as at 25, constituting braces,which are engaged by the shaft 26, extending through the body 24, seeFigs. 3 and 5. The body 24 is enlarged, at its end 27, and a thumb-screw28 is threaded through the enlarged portion 27 of the Ushaped body, theinner end of said screw 28 engaging the shaft or bar 26 for locking thesame in an adjusted position, whereby the frictional-wheel 29, carriedby axle or bolt 30, may be retained in frictional contact with the rearwheel 31 of the bicycle. Fixedly secured to the frictional wheel orroller 29, is a pulley 32. The belt 22 is carried by pulleys 15 and 32,and said belt is retained tight or taut upon said pulleys through themedium of the tighteningulley 20.

T e rear forks 2 are positioned between the sides of the U-shaped body24, and are clamped by said sides by extending thumbbolt 33 through oneof the sides and threading it into the opposite side, see 3. Through themedium of the thumb-screw 28, and the braces 25, the shaft or bar 26 canbe retained in a rigid position upon the rear clamp 23, while the shaftor bar 11 carrying the grinding-wheel can be adjusted to suit the heightof the operator, and securely fastened in the adjusted position.

From the foregoing description, it is to be noted that my grindingattachment comprises a front clamping device, carrying a grinding-wheeland a pulley, and a rear clamping-device, carrying a friction-wheel andpulley, the pulleys of the two devices being connected by an endlessbelt.

What I claim is:

1. In a grinding attachment for bicycles, the combination of a clampprovided with a block, a shaft adjustably mounted upon said block, meanscarried by said block and engaging the same and securing the shaft in anadjusted position, a grinding-wheel carried by said shaft, a pulleyfixedly secured to said grinding-wheel, a friction-wheel supportedcontlguous to said grinding-wheel, and means connecting saidfriction-wheel and grindingwheel, whereby, when rotary movement isimparted to said friction-wheel, similar movement will be imparted tosaid grindingwheel.

2. In a grinding attachment, the combination of a clamp, a block securedto said clamp, a grinding-wheel carried by said block, a pulley securedto said grindingwheel, a friction-wheel positioned contiguous to saidgrinding-wheel, a pulley fixedly secured to said friction-wheel, a beltmounted upon said pulleys, an arm provided with a lower, bifurcated endengaging said block,

means adjustably securing said arm to said block, and a tighteningpulley carried by said arm and engaging said belt for retaining the samein a tight condition.

3. A grinding attachment for bicycles, comprising a clamp provided witha substantially Ushaped, resilient body having portions bent backparallel therewith and the extreme outer ends of said bent-portionsturned outwardly and constituting braces, a shaft extending through saidbody and engaging said outwardly turned ends, means for securing saidshaft in an adjusted position upon said body, a driving-member carriedby said shaft, a driven-member positioned contiguous to saiddriving-member, and means connecting said driving-member anddriven-member, whereby, when move ment is imparted to saiddriving-member, similar movement will be imparted to said driven-member.

4. In a grinding attachmentfor bicycles, the combination with a frame,of a pair of clamps supported upon said frame, each clamp positionedupon a plurality of bars of said frame, a driving-member adjustablymounted upon one of said clamps, means securing said driving-member inan adjusted position, a driven-member adjustably mounted upon the otherclamp, means for securing said driven-member in an adjusted positionupon said clamp, and. means connecting said driving-member anddrivenmember, whereby movement of one of said members will impartsimilar movement to the other member.

5. In a grinding attachment for bicycles, the combination of a clamp,provided with a substantially U-shaped, resilient body, means forclamping said body upon an object, a-shaft adjustably mounted upon saidbody, means for securing said shaft in an adjusted position upon saidbody, a frictionwheel carried by said shaft, and a pulley carried bysaid shaft and fixedly secured against independent, rotary movement withrespect to said friction-wheel.

6. The combination with a bicycle frame, of a clamp engaging said frame,said clamp provided with parallel sides, means extending transversely ofsaid sides and adapted to draw the same together for clamping saidframe, a shaft engaging and slidably mounted upon said clamp, lockingmeans for securing said shaft in an adjusted position, and afriction-Wheel and a pulley carried by said shaft.

7. In a device of the character described, the combination with asupport, of a singlepiece clamp provided with a body portion and withportions bent back parallel to said body portion, means extendinthroughsaid body portion and said paralle portions for drawing the sidesof the body portion and the parallel portions together, a friction-Wheel and a pulle and means supporting said friction-whee and pulleyupon said clamp.

8. In a grinding attachment for bicycles,

5 the combination of a clamp, comprising a pair of clamp-members, onedetaehably se cured to the other member, a shaft positioned conti uousto one of said members,

means detachably and adjustably securing 10 said shaft to said member, agrinding-wheel and a pulley positioned contiguous to said shaft, andmeans rotatably securing said grinding-Wheel and pulley to said shaft.

In testimony whereof l hereunto allix my signature in presence of twoWitnesses.

JAMES P. GRANT.

